Rubens Barrichello is optimistic that his Williams team will prove to be one of the surprises of the year after encouraging times in recent tests.
Williams has spent much of the winter doing long runs and proving its reliability, but Nico Hulkenberg was quickest on Friday at Barcelona - and Barrichello thinks that performance has changed perceptions of their team.
"I think Nico's time on Friday was the very first time we tried low fuel in the car, and we surprised a few people, so all of a sudden Williams is being talked about in the paddock," he said.
"This winter it was very, very easy to become the hero of the winter test. If I took fuel out at every test I would've been first at every test, but would that have taught me what I now know from the car? I don't think so."
Thought reluctant to predict where Williams would be in the pecking order, Barrichello is confident that the team has gained ground during testing.
"We have improved - we can only say for ourselves - but we have improved a good second from Valencia," he said.
"We feel competitive, but I think Williams-Cosworth can be one of the teams to surprise people this year. But like I said it's really, really difficult and I'm just keeping myself very clear, my feet on the ground, and just working as hard as I can. But I feel the car is on a competitive level."
He is also certain that Williams is in great shape reliability-wise.
"The main topic of the first three tests, at Valencia, Jerez and Jerez, was to absolutely nail reliability - and we have done that very, very, very well," Barrichello said.